Auto merge of #55114 - oli-obk:fx#map, r=nikomatsakis

Deprecate the `FxHashMap()` and `FxHashSet()` constructor function hack

src/test/compile-fail-fulldeps/dropck_tarena_cycle_checked.rs

@@ -122,6 +122,6 @@ fn f<'a>(arena: &'a TypedArena<C<'a>>) {
 }
 
 fn main() {
-    let arena = TypedArena::new();
+    let arena = TypedArena::default();
     f(&arena);
 } //~^ ERROR `arena` does not live long enough

src/test/compile-fail-fulldeps/dropck_tarena_unsound_drop.rs

@@ -47,7 +47,7 @@ impl<'a> HasId for &'a usize { fn count(&self) -> usize { 1 } }
 fn f<'a>(_arena: &'a TypedArena<C<'a>>) {}
 
 fn main() {
-    let arena: TypedArena<C> = TypedArena::new();
+    let arena: TypedArena<C> = TypedArena::default();
     f(&arena);
 } //~^ ERROR `arena` does not live long enough
 

src/test/run-pass-fulldeps/dropck_tarena_sound_drop.rs

@@ -46,6 +46,6 @@ impl<'a> HasId for &'a usize { fn count(&self) -> usize { 1 } }
 fn f<'a, 'b>(_arena: &'a TypedArena<C<'b>>) {}
 
 fn main() {
-    let arena: TypedArena<C> = TypedArena::new();
+    let arena: TypedArena<C> = TypedArena::default();
     f(&arena);
 }

src/test/run-pass-fulldeps/regions-mock-tcx.rs

@@ -133,8 +133,8 @@ fn compute_types<'tcx,'ast>(tcx: &mut TypeContext<'tcx,'ast>,
 }
 
 pub fn main() {
-    let ty_arena = TypedArena::new();
-    let ast_arena = TypedArena::new();
+    let ty_arena = TypedArena::default();
+    let ast_arena = TypedArena::default();
     let mut tcx = TypeContext::new(&ty_arena, &ast_arena);
     let ast = tcx.ast(ExprInt);
     let ty = compute_types(&mut tcx, ast);